Telling whether the user is at the console

[Peter Scott]

What's the easiest way to tell from (1) a shell script; (2) a C
program, whether the user process that called either of them was
logged in at the console?  I've looked at /etc/utmp, but it seems
that there should be an easier way.

-- 
This is news.  This is your       |    Peter Scott, NASA/JPL/Caltech
brain on news.  Any questions?    |    (pjs at aristotle.jpl.nasa.gov)